This invention relates generally to electrical distribution centers and more specifically to electrical distribution centers that use bus plates for interconnecting terminals that are mated to electrical or electronic devices or electrical connectors of wiring harnesses.
U.S. Pat. No. 5,023,752 granted to Gary C. Detter et al Jun. 11, 1991 discloses such an electrical distribution center for automotive use. This electrical distribution center utilizes stamped metal circuit components to conduct current through internal circuitry. It involves multiple layers of stamped metal circuit components that are heat-staked into corresponding tracks of thermoplastic insulator plates. These plate assemblies are stacked and secured together in a unit handled bussing sub-assembly. The stamped metal circuit components include male blade terminals that pass through slots of the insulator plates and project outwardly of the sub-assembly to mate to electrical connectors of wiring harnesses or to electrical and electronic devices via double ended female terminals. The bussing sub-assembly is disposed and secured within a two-piece thermoplastic housing that has plug-in portions for receiving the electrical connectors of the wiring harnesses and the electrical and electronic devices.
While this electrical distribution center has been successfully used by General Motors Corporation in its Saturn automotive vehicles, it has a significant drawback in that changes in the internal circuitry are expensive due largely to the inflexibility of the stamped metal circuit components. Each stamped metal circuit component is produced from a unique stamping die and a unique mold die is used to produce each insulator plate with the corresponding circuit tracks. Because of this situation, any change in circuit configuration, regardless of how minor, forces tool revisions for the stampings and insulator plates. This is not only costly but also requires long lead times for the tool revisions. Moreover, completely new tooling may be required if significant changes are involved.
It is also known from U.S. Pat. No. 4,684,765 granted to Lawrence R. Beck et al Aug. 4, 1987 and junction blocks produced by the Packard Electric Division of General Motors Corporation to provide a junction block comprising double ended male blade terminals that are insert molded into a housing plate and upper and lower bussing plates each comprising a routing board and solid core copper wire routed onto the routing board. Each end of the male blade terminals projects outwardly of the housing plate and each end has a wire receiving slot of the insulation displacement type near the base of its blade. The upper and lower bussing plates are assembled to the housing plate by pressing the upper and lower bussing plates over the projecting ends of the male blade terminals. This action forces the solid core wire into the wire receiving slots creating bussing circuits between the male blade terminals. When electrical female connectors of wiring harnesses are mated to each side of the junction block, the routed wires provide for bussing between the various wiring harnesses.
As indicated in the Beck patent, the routing of the wire onto the routing boards is an automatic process which can quickly be reprogrammed to create any configuration of wire routing. Thus, bussing circuit configurations are easy to create and change with minimal cost and time. This routed wire technology provides flexibility in bussing. However, it too has a major drawback in that the present routed wire technology has a relatively low current carrying capability and consequently it is not suitable for use in automotive applications such as electrical distribution centers that require relatively high current carrying capability for many of the circuits.